Question

Определите массовые доли элементов соответствующих количественному составу дигидрофосфата натрия? Ответ приведите с точностью до целых.

Answer 1

Ответ:

Дано:

NaH₂PO₄

Найти:

w(Na), w(H), w(P), w(O)

Решение:

M(NaH₂PO₄) = 23+1·2+31+ 16·4= 120 г\моль

w(Na) = 23·1\120 = 0,2, или 20%

w(H) = 1·2\120= 0,02, или 2%

w(P) = 31·1\120 = 0,26, или 26%

w(O) = 16·4\120 = 0,53, или 53%

Answer 2

Mass Fractions of Elements in Sodium Dihydrogen Phosphate

To determine the mass fractions of elements in sodium dihydrogen phosphate (NaH2PO4), we need to consider the atomic masses of each element and their respective quantities in the compound.

The molecular formula of sodium dihydrogen phosphate is NaH2PO4. From this formula, we can identify the following elements and their respective quantities:

- Sodium (Na): 1 atom - Hydrogen (H): 2 atoms - Phosphorus (P): 1 atom - Oxygen (O): 4 atoms

To calculate the mass fractions, we need to know the atomic masses of each element. Here are the atomic masses of the elements involved:

- Sodium (Na): 22.99 g/mol - Hydrogen (H): 1.01 g/mol - Phosphorus (P): 30.97 g/mol - Oxygen (O): 16.00 g/mol

Now, let's calculate the mass fractions of each element:

1. Sodium (Na): - Mass of Na = 1 atom * 22.99 g/mol = 22.99 g - Mass fraction of Na = (Mass of Na / Total mass of NaH2PO4) * 100%

2. Hydrogen (H): - Mass of H = 2 atoms * 1.01 g/mol = 2.02 g - Mass fraction of H = (Mass of H / Total mass of NaH2PO4) * 100%

3. Phosphorus (P): - Mass of P = 1 atom * 30.97 g/mol = 30.97 g - Mass fraction of P = (Mass of P / Total mass of NaH2PO4) * 100%

4. Oxygen (O): - Mass of O = 4 atoms * 16.00 g/mol = 64.00 g - Mass fraction of O = (Mass of O / Total mass of NaH2PO4) * 100%

To calculate the total mass of NaH2PO4, we need to sum up the masses of all the atoms in the compound:

Total mass of NaH2PO4 = Mass of Na + Mass of H + Mass of P + Mass of O

Now, let's calculate the mass fractions using the given atomic masses and quantities of each element in sodium dihydrogen phosphate.

Calculation of Mass Fractions

1. Sodium (Na): - Mass of Na = 1 * 22.99 g/mol = 22.99 g - Total mass of NaH2PO4 = 22.99 g + 2.02 g + 30.97 g + 64.00 g = 119.98 g - Mass fraction of Na = (22.99 g / 119.98 g) * 100% = 19.16%

2. Hydrogen (H): - Mass of H = 2 * 1.01 g/mol = 2.02 g - Mass fraction of H = (2.02 g / 119.98 g) * 100% = 1.68%

3. Phosphorus (P): - Mass of P = 1 * 30.97 g/mol = 30.97 g - Mass fraction of P = (30.97 g / 119.98 g) * 100% = 25.81%

4. Oxygen (O): - Mass of O = 4 * 16.00 g/mol = 64.00 g - Mass fraction of O = (64.00 g / 119.98 g) * 100% = 53.35%

Summary of Mass Fractions

The mass fractions of elements in sodium dihydrogen phosphate (NaH2PO4) are approximately as follows:

- Sodium (Na): 19.16% - Hydrogen (H): 1.68% - Phosphorus (P): 25.81% - Oxygen (O): 53.35%

Please note that these values are approximate and have been calculated based on the given atomic masses and quantities of each element in the compound.